The present invention generally relates to methods and devices for supporting areas within an article of furniture. More particularly, the present invention relates to mattresses or other spring-supported bedding and seating articles with edge supports.
An innerspring mattress is generally formed by encasing a spring core with padding materials and upholstery layers. The spring core includes rows of coil springs, sinusoidal wires, and border wires. The rows of coil springs extend generally along the intended width and length of the mattress. The border wires and sinusoidal wires interconnect the coil springs. Typically, the spring core includes a top border wire that extends around the perimeter of the rows of coil springs near the top of the edge coil springs and a bottom border wire that extends around the perimeter of the rows of coil springs near the bottom of the edge coil springs. Edge coil springs are the first and last coil springs in each row, including the rows that extend along the width of the mattress as well as the rows that extend along the length of the mattress. The sinusoidal wires extend across the rows of coil springs and interconnect the coil springs of the rows together and connect the coil springs to the border wires.
The edges of a mattress tend to deform or wear faster than the rest of the mattress. The edges of a mattress are susceptible to deformation or wear because the edge coil springs lack the additional support of having interconnected adjacent coil springs on all sides as seen in the non-edge coil springs and because people often sit near the edges of the mattresses. Therefore the edges of the mattress tend to sag over a period of time.
Mattress manufactures have used foam edge supports to reinforce the edges of the mattresses. Typically, an edge support extends lengthwise along the length of the border wires and widthwise from the top and bottom border wires. The edge support also extends from and between the border wires inwardly toward the spring coils and defines a thickness of the edge support. In general, the thickness of the edge support provides the reinforcement to the edge of the mattress by positioning portions of the foam material of the edge support between the top and bottom border wires such that the foam material resists the compression of the top and bottom border wires. In some edge supports, the edge support may extend partially into or around the edge spring coils to provide additional reinforcement.
Typically, foam edge supports are made through an extrusion process at a first facility and then shipped to a second facility where the mattresses are assembled. However, known edge supports are relatively thick, which may add to the cost of shipping the edge supports. For example, the thickness of the edge supports is usually great enough to prevent the rolling of the edge supports and instead requires the edge supports to be stacked during shipping and storage. Moreover, the thickness of the edge supports may limit the edge support's ability to be wrapped around the corners of the spring cores.